#wrap{
    width: 100%;
    height: 100%;
    #beginMask{
        position: absolute;
        width: 100%;
        height: 100%;
        z-index: 5;
        .up{
            height: 50%;
            background-color: deepskyblue;
            transition: 1s height;
        }
        .down{
            position: absolute;
            width: 100%;
            height: 50%;
            background-color: deepskyblue;
            bottom: 0;
            transition: 1s height;
        }
        .line{
            position: absolute;
            height: 4px;
            width: 0;
            background-color: white;
            top: 50%;
            left: 0;
            margin-top: -2px;
            transition: 1s width;
        }
    }
}
